[v6ops] Fwd: I-D Action: draft-yourtchenko-chown-rupik-v6ops-dad-3x-00.txt

Tim Chown <tjc@ecs.soton.ac.uk> Fri, 04 July 2014 16:24 UTC

From: Tim Chown <tjc@ecs.soton.ac.uk>
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Date: Fri, 04 Jul 2014 17:24:33 +0100
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Subject: [v6ops] Fwd: I-D Action: draft-yourtchenko-chown-rupik-v6ops-dad-3x-00.txt
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Hi,

Just a quick note to explain this short draft.  If there is interest we’d be happy to present for 5-10 mins in Toronto.

We had a strange issue with ND management tools on our vendor’s wireless LAN controller, and as a result it was sending three copies of certain ND messages in very quick succession. On Mac OS X, this was triggered a positive DAD event, which meant OS X would deprecate the tentative address, and IPv6 would be disabled.

Certain other OSes continued to configure the interface successfully though, not considering the messages a DAD event. Which led to a confusing situation for the administrator to debug.

There’s probably a couple of resulting issues here:

1) There is different behaviour in response to triplicates of certain ND messages on different OSes. Is the preferred behaviour what the RFC says? We should certainly try to make the behaviour more predictable (even if the underlying cause is not a common one).

2) Is there a new DAD attack here beyond the classic “No, I already have that address, you can’t have it” one?  You could sniff for ND messages and generate duplicates to prevent (at least an OS X device) from configuring IPv6 successfully.  The rapid duplicates might not be looked for by existing tools that look for the classic DAD attack in action.

Tim

Begin forwarded message:

> From: internet-drafts@ietf.org
> Subject: I-D Action: draft-yourtchenko-chown-rupik-v6ops-dad-3x-00.txt
> Date: 4 July 2014 14:17:07 BST
> To: i-d-announce@ietf.org
> Reply-To: internet-drafts@ietf.org
> 
> 
> A New Internet-Draft is available from the on-line Internet-Drafts directories.
> 
> 
>        Title           : DAD And Packet Triplication
>        Authors         : Andrew Yourtchenko
>                          Tim Chown
>                          Seb Rupik
> 	Filename        : draft-yourtchenko-chown-rupik-v6ops-dad-3x-00.txt
> 	Pages           : 4
> 	Date            : 2014-07-04
> 
> Abstract:
>   This draft captures the observation of IPv6 Duplicate Address
>   Detection behavior in the case of excessive packet replication (3x),
>   the latter caused by by a misbehaving device in the network.  Also it
>   compares the operation of IPv6 vs. IPv4 as a result.
> 
> 
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-yourtchenko-chown-rupik-v6ops-dad-3x/
> 
> There's also a htmlized version available at:
> http://tools.ietf.org/html/draft-yourtchenko-chown-rupik-v6ops-dad-3x-00

[v6ops] Fwd: I-D Action: draft-yourtchenko-chown-… Tim Chown
Re: [v6ops] Fwd: I-D Action: draft-yourtchenko-ch… 神明達哉